As the below-zero temperatures continue in northern Illinois, I rejoice when each morning a fox sparrow pecks on the ground for fallen thistle seed or when a red-breasted nuthatch grabs a sunflower oiler seed from the feeder.
Many days of extreme cold can be difficult for these songbirds, which weigh less than half an ounce. Pick up a few small paper clips to get a sense of how much these birds weigh, then ponder how they are able to survive winter.
Feeding birds year-round doesn’t necessarily ensure their survival. But when it gets really cold in winter, that extra source of fat and protein in the form of sunflower seeds and suet might be just what they need to make it through a frigid evening, experts say.
So in a small way, I may be helping the chickadees, woodpeckers, nuthatches, juncos, American tree sparrows, fox sparrow, American goldfinches and northern cardinals that have been out feeding in the yard these last few frigid weeks.
The truth is, these birds wouldn’t be here in our cold northern Illinois climate if they didn’t have other ways to cope with cold, snow, ice and wind, as well as finding food. Indeed, the birds that grace our neighborhoods in winter find food in the wild without visiting feeders.
The downy woodpecker, for example, uses its hammer-like bill and long tongue to extract overwintering insect larvae and pupae from tree trunks and branches. Chickadees also find dormant insects or spiders on or under tree bark in winter. Like nuthatches, they hide food from the wild as well as our feeders for later retrieval.
American tree sparrows spend time in fields eating grass and sedge seeds from plants like goldenrod, asters and other forbs (herbaceous flowering plants). When their food source is covered up by a huge snow, they frequent backyards, where feeder seeds may be more exposed. Trees loaded with berries also help sustain birds such as house finches and woodpeckers in winter.
These birds have anatomical adaptations to keep the cold and wind at bay. The outer feathers of small songbirds we see in winter are contoured to block wind. Downy feathers closer to the skin trap warm air, just like the thermal underwear worn next to our skin to protect us from cold.
Birds also ruffle their feathers to increase their natural insulation, and tuck their bills into shoulder feathers to reduce heat loss.
But what about their featherless legs?
Imagine standing outside on a cold February morning wearing no socks or shoes. Some bird species have an adaptation called counter heat exchange. They lower the temperature in their feet so it’s close to freezing, saving more warmth for other parts of their bodies. After especially frigid days, however, it’s not rare to see a mourning dove with one of its toes frozen off.
Small songbirds burn calories fast and lose heat fast, so they need to eat a lot. Often, before a storm is approaching, many sparrows, juncos and other songbirds congregate on or below the feeders to stuff themselves. Then they escape to a warmer place to wait out the storm using their extra fat reserves to stay alive.
Birds know where they can go to keep out of the wind, as well as where they can sleep at night. Small songbirds roost during storms and sleep at night in natural tree cavities, bird houses, dense vegetation such as evergreens, brush piles and even beneath porches. Facebook users recently posted photos of juncos chilling underneath picnic tables or hunkered in a huge stack of twigs, left untouched during fall cleanup, a good practice.
Our cedars and spruces provide shelter at night for the birds we see during the day. If I’m up at sunrise, I sometimes see a junco emerge from a cedar to look for seed on the ground beneath feeders. There are plenty of other places to go nearby, such as the group of evergreens down the block or stands of trees, shrubs and grasses next to the fire station across the street.
Some birds, like chickadees, lower their body temperature and metabolism during frigid nights. They can lower their normal temperature of 105 degrees to as low as 50 degrees. While they sleep in what’s called a state of torpor, they will not need to rely on as much of their fat reserves. At dawn, they shiver to raise their body temperature to normal, then fly away to start eating.
It’s amazing to think of what birds can do to survive winter without any help from us. However, birds do need us during this huge cold snap, and the best way to help them is to put out food that’s easy to eat and high in fat.
Tonight, more black oil sunflower seeds and thistle seeds will be added to the feeders while the birds slumber in their chosen winter shelters. Then, hopefully tomorrow morning, the fox sparrow, cardinals, goldfinches and juncos will be back to sustain me in this harsh winter.
Sheryl DeVore has worked as a full-time and freelance reporter, editor and photographer for the Chicago Tribune and its subsidiaries. She’s the author of several books on nature and the environment and co-author of a coming book on “Birds of the Midwest,” to be published by Timber Press. Send story ideas and thoughts to sheryldevorewriter@gmail.com.
